switching from Conventional to synthetic at 96k
my 2003 4.0l has almost 96k on it and supposedly has been run all the way till now on conventional. I am the 3rd or 4th owner. the first owner put 55k on it in 3 years. The truck runs great and looks amazing. I'm afraid it will leak by changing it to synthetic, but also wonder if it will be better for the motor by running synthetic because the motor definitely has been broken in at this point. Mobil 1 says their high mileage brand is made for an application like this of changing from conv. to syn. and then changing in the different intervals before you settle in to a set drain interval. Everybody says that synthetic is the way to go and it's only a dollar more a quart, but then the old saying goes, if it aint broke dont fix it.... well it aint broke but maybe the syn. oil won hurt it and ppl say it turns off the "wear switch" on the seals and other say this will **** up the seals. what does everybody think about this. I've put 100k on a ford escort that has over 250k and I ran pennzoil conv and it still doesn't leak oil.
Last edited by Liquidswords32; 03-01-2011 at 08:00 PM.